QY55KA-Y Lower Telescopic Cylinder Seal Kit S33
Lower telescopic cylinders carry high structural loads and spend much of their life inside the boom. S33 kit selection must follow the cylinder label and measured sealing components.
| Customer priority | Will it match the lower telescopic stage, and are the rod, tube and guides reusable? |
| Evidence needed | Lower-stage cylinder number Rod and bore dimensions Piston and gland seal profiles Guide/wear ring sizes Rod chrome and tube condition
|
Diagnosis Before Replacement
Boom creep can come from piston seals, holding valves or control leakage. External oil points more toward rod sealing, but surface damage must be corrected.
Fit, Test and Handover
Support and retract the boom under the service procedure. Keep components organized by direction, protect seal lips, bleed the cylinder and check synchronized extension plus holding.
Useful Internal References
XCMG Balance Valve 803001825 · XCMG QY50K Hydraulic Pump 803000260
FAQ
Does S33 identify every seal?
Confirm the actual cylinder assembly.
Can valve leakage mimic seal failure?
Yes, isolate the cylinder hydraulically.
Why inspect guides?
Worn guides allow side load and repeat damage.
Export preparation: Each seal group is bagged by location and shielded from deformation.
